From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: deepak1556 <hop2deep@gmail.com>
Date: Tue, 17 Aug 2021 22:42:42 -0700
Subject: feat: expose raw response headers from URLLoader

With https://chromium-review.googlesource.com/c/chromium/src/+/2856099
unfiltered response headers are only available via trusted channel
through //services/network/public/mojom/devtools_observer.mojom.
https://github.com/electron/electron/pull/30503/commits/28f4da1582d046e96cb58f3cbb590503e89dfd0d
was an attempt to use this interface but given the original response is
signalled on a different interface via URLLoaderClient::OnReceiveResponse
it is harder to sync these data from two different channels for a synchronous
event emitted on the SimpleURLLoaderWrapper::OnResponseStarted.

This patch does the minimal approach to add back the raw response
headers, moving forward we should find a way in upstream to provide
access to these headers for loader clients created on the browser process.

diff --git a/services/network/public/cpp/resource_request.cc b/services/network/public/cpp/resource_request.cc
index 28bf295032c89dc7831d341cef95d11c53ade3b3..9f82e5202f2fe275d738dcadf41c535ad9f8df94 100644
--- a/services/network/public/cpp/resource_request.cc
+++ b/services/network/public/cpp/resource_request.cc
@@ -155,6 +155,7 @@ ResourceRequest::TrustedParams& ResourceRequest::TrustedParams::operator=(
   allow_cookies_from_browser = other.allow_cookies_from_browser;
   include_request_cookies_with_response =
       other.include_request_cookies_with_response;
+  report_raw_headers = other.report_raw_headers;
   cookie_observer =
       Clone(&const_cast<mojo::PendingRemote<mojom::CookieAccessObserver>&>(
           other.cookie_observer));
@@ -185,6 +186,7 @@ bool ResourceRequest::TrustedParams::EqualsForTesting(
     const TrustedParams& other) const {
   return isolation_info.IsEqualForTesting(other.isolation_info) &&
          disable_secure_dns == other.disable_secure_dns &&
+         report_raw_headers == other.report_raw_headers &&
          has_user_activation == other.has_user_activation &&
          allow_cookies_from_browser == other.allow_cookies_from_browser &&
          include_request_cookies_with_response ==
diff --git a/services/network/public/cpp/resource_request.h b/services/network/public/cpp/resource_request.h
index 79851e979be2dbba27690e1e7807afcb252d3d23..5b766862d8c9e08ce55f328eaf9314a5d3a662c0 100644
--- a/services/network/public/cpp/resource_request.h
+++ b/services/network/public/cpp/resource_request.h
@@ -71,6 +71,7 @@ struct COMPONENT_EXPORT(NETWORK_CPP_BASE) ResourceRequest {
     bool has_user_activation = false;
     bool allow_cookies_from_browser = false;
     bool include_request_cookies_with_response = false;
+    bool report_raw_headers = false;
     mojo::PendingRemote<mojom::CookieAccessObserver> cookie_observer;
     mojo::PendingRemote<mojom::TrustTokenAccessObserver> trust_token_observer;
     mojo::PendingRemote<mojom::URLLoaderNetworkServiceObserver>
diff --git a/services/network/public/cpp/url_request_mojom_traits.cc b/services/network/public/cpp/url_request_mojom_traits.cc
index 1f18c9cbe892c24cde8d1430afa882f2d5d9879d..9817380cf1169f9c778f236a316b1928b501c68a 100644
--- a/services/network/public/cpp/url_request_mojom_traits.cc
+++ b/services/network/public/cpp/url_request_mojom_traits.cc
@@ -96,6 +96,7 @@ bool StructTraits<network::mojom::TrustedUrlRequestParamsDataView,
   out->allow_cookies_from_browser = data.allow_cookies_from_browser();
   out->include_request_cookies_with_response =
       data.include_request_cookies_with_response();
+  out->report_raw_headers = data.report_raw_headers();
   out->cookie_observer = data.TakeCookieObserver<
       mojo::PendingRemote<network::mojom::CookieAccessObserver>>();
   out->trust_token_observer = data.TakeTrustTokenObserver<
diff --git a/services/network/public/cpp/url_request_mojom_traits.h b/services/network/public/cpp/url_request_mojom_traits.h
index 6778aaaa46cbab86de77f75b18226a51833de450..d21a13ec46e13a6c5ed345ff99ebec25460a40af 100644
--- a/services/network/public/cpp/url_request_mojom_traits.h
+++ b/services/network/public/cpp/url_request_mojom_traits.h
@@ -76,6 +76,10 @@ struct COMPONENT_EXPORT(NETWORK_CPP_BASE)
       const network::ResourceRequest::TrustedParams& trusted_params) {
     return trusted_params.include_request_cookies_with_response;
   }
+  static bool report_raw_headers(
+      const network::ResourceRequest::TrustedParams& trusted_params) {
+    return trusted_params.report_raw_headers;
+  }
   static mojo::PendingRemote<network::mojom::CookieAccessObserver>
   cookie_observer(
       const network::ResourceRequest::TrustedParams& trusted_params) {
diff --git a/services/network/public/mojom/url_request.mojom b/services/network/public/mojom/url_request.mojom
index 7c006ab576a03d14549f3a0c7b3fb35cf21fee0a..5cd81ab4de26bf9f174a5571d3c41fd404049a61 100644
--- a/services/network/public/mojom/url_request.mojom
+++ b/services/network/public/mojom/url_request.mojom
@@ -81,6 +81,9 @@ struct TrustedUrlRequestParams {
   // client which should not be able to see them.
   bool include_request_cookies_with_response = false;
 
+  // [Electron] Whether to provide unfiltered response headers.
+  bool report_raw_headers;
+
   // Observer which should be notified when this URLRequest reads or writes
   // a cookie. If this is set to non-null, the observer passed to
   // URLLoaderFactory will be ignored.
diff --git a/services/network/public/mojom/url_response_head.mojom b/services/network/public/mojom/url_response_head.mojom
index 3450c15835d8b792f37764f6edc4a4560be435ef..b1034aa141d6121f8e1524fb34a28a040a280420 100644
--- a/services/network/public/mojom/url_response_head.mojom
+++ b/services/network/public/mojom/url_response_head.mojom
@@ -13,6 +13,7 @@ import "services/network/public/mojom/attribution.mojom";
 import "services/network/public/mojom/fetch_api.mojom";
 import "services/network/public/mojom/http_request_headers.mojom";
 import "services/network/public/mojom/ip_address_space.mojom";
+import "services/network/public/mojom/http_raw_headers.mojom";
 import "services/network/public/mojom/ip_endpoint.mojom";
 import "services/network/public/mojom/load_timing_info.mojom";
 import "services/network/public/mojom/network_param.mojom";
@@ -44,6 +45,9 @@ struct URLResponseHead {
   // The response headers or NULL if the URL type does not support headers.
   HttpResponseHeaders headers;
 
+  // Actual response headers, as obtained from the network stack.
+  array<HttpRawHeaderPair> raw_response_headers;
+
   // The mime type of the response.  This may be a derived value.
   string mime_type;
 
diff --git a/services/network/url_loader.cc b/services/network/url_loader.cc
index 84043fea7be3dc13677ff78d262ce0dc0e531963..512f64f44c5edfacdab094db22f0fca0354a99ca 100644
--- a/services/network/url_loader.cc
+++ b/services/network/url_loader.cc
@@ -721,6 +721,7 @@ URLLoader::URLLoader(
         request.trusted_params->allow_cookies_from_browser;
     include_request_cookies_with_response_ =
         request.trusted_params->include_request_cookies_with_response;
+    report_raw_headers_ = request.trusted_params->report_raw_headers;
   }
 
   // Store any cookies passed from the browser process to later attach them to
@@ -759,7 +760,7 @@ URLLoader::URLLoader(
         &URLLoader::IsSharedDictionaryReadAllowed, base::Unretained(this)));
   }
 
-  if (devtools_request_id()) {
+  if (devtools_request_id() || report_raw_headers_) {
     url_request_->SetResponseHeadersCallback(base::BindRepeating(
         &URLLoader::SetRawResponseHeaders, base::Unretained(this)));
   }
@@ -1726,6 +1727,19 @@ void URLLoader::OnResponseStarted(net::URLRequest* url_request, int net_error) {
   }
 
   response_ = BuildResponseHead();
+  if (raw_response_headers_ && report_raw_headers_) {
+    std::vector<network::mojom::HttpRawHeaderPairPtr> header_array;
+    size_t iterator = 0;
+    std::string name, value;
+    while (raw_response_headers_->EnumerateHeaderLines(&iterator, &name, &value)) {
+      network::mojom::HttpRawHeaderPairPtr pair =
+          network::mojom::HttpRawHeaderPair::New();
+      pair->key = name;
+      pair->value = value;
+      header_array.push_back(std::move(pair));
+    }
+    response_->raw_response_headers = std::move(header_array);
+  }
   DispatchOnRawResponse();
 
   // Parse and remove the Trust Tokens response headers, if any are expected,
diff --git a/services/network/url_loader.h b/services/network/url_loader.h
index 4604794bc6f71672a60ebbd8c601828c3f63f1fe..e3409b9a56cbd1f57cbc77f0a951e66c05f22d0e 100644
--- a/services/network/url_loader.h
+++ b/services/network/url_loader.h
@@ -673,6 +673,8 @@ class COMPONENT_EXPORT(NETWORK_SERVICE) URLLoader
   std::unique_ptr<ResourceScheduler::ScheduledResourceRequest>
       resource_scheduler_request_handle_;
 
+  // Whether client requested raw headers.
+  bool report_raw_headers_ = false;
   bool enable_reporting_raw_headers_ = false;
   bool seen_raw_request_headers_ = false;
   // Used for metrics.
